/**
 * number string boolean null undefined 
 * Array Object Function
 */
var num: number = 10;
var str: string = 'hello';
var b: boolean = true;
var arr: string[] = ['html', 'css', 'js']
var arr2: Array<number> = [1, 2, 3];

var obj: Object = {
    name: "lisi",
    age: 20
}

function go(): void {
    console.log("go");
}
function show(val: string): string {
    return val
}

function http(method = "get"): void {
    console.log(method);
}

http();
http('post');

function getInfo(name: string, age?: number): void {
    console.log(name, age);
}
getInfo("lisi");
getInfo("lisi", 19);

